A lot of online activity last night. It's "your voice, your vote." With just 25 days to go. Abc's jon karl has all the highlights from danville, kentucky. No throat-clearing last night. These guys were going at it from the start. Reporter: They sure were, george. This was a clash of ideas. A clash of styles. And I would say the liveliest vice presidential debate we have ever seen. This one got personal. Jack kennedy lowered taxes -- now, you're jack kenn Rr: Barb after barb. I know you're under a lot of duress to make up for lost ground. But I think people will be better served if we don't keep interrupting each other. Well, don't take all of the four minutes then. Reporter: Biden was often dominant. Maybe a little too dominant. Republicans claimed he interrupted ryan 82 times. Often breaking out in laughter. Even when ryan was talking about iranian nukes. And all I have to point to -- Reporter: Biden was all-smiles when he accused ryan of basically not telling the truth. This is a bunch of stuff. Look, here's the deal. What does that mean, a bunch of stuff? It's -- it's irish. We irish call it mularkey. Reporter: They disagreed on virtually everything. From syria, to medicare. Now, they have a new plan. Trust me. It's not going to cost you anymore. Folks, follow your instincts on this. They got caught with their hands in the cookie jar, turning medicare into a piggy bank for obama care. Reporter: Martha raddatz pressed both of them. Challenging biden to explain the white house's shifting stories on the attack that killed the u.S. Ambassador to libya. When people in the consulate first saw armed men attacking, there were no protests. Why did that go on for weeks? That's what we were told by the intelligence community. It's indicative of a broader problem. That what we're watching on our tv screens is the unraveling of the obama foreign policy. Reporter: Score one for ryan there. But when ryan slammed the administration's $800 billion stimulus bill, biden was ready with this. Sent me two letters saying, by the way, can you send me some stimulus money for companies here in the state of wisconsin. We sent millions of dollars. You know -- you did ask for stimulus money, correct? Sure he did. For two occasions, we advocated for constituents applying for grants. That's what we do. I love that. This is such a bad program. And he writes me a letter saying, the reason we need this stimulus, it will create growth and jobs. His words. Reporter: Unlike the president, biden slammed ryan over romney's infamous comments about the 47% of americans who don't pay income taxes. Ryan turned it back on biden. I think the vice president very well knows that sometimes the words don't come out of your mouth the right way. Reporter: Now, there will be a lot of discussion over who was stronger last night. Biden or ryan. But I've got to tell you, around here, there was one clear consensus winner. And that was the moderator, martha raddatz, who taught the world what we all know around here, george. You don't mess with martha. That is for sure. It was a lively time.

This transcript has been automatically generated and may not be 100% accurate.

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